This concrete subclass of TimeZone is a simple
implementation of that abstract class, and is suitable for
use in locales that use the Gregorian calendar. Programs do
not usually need to instantiate this class directly;
instead, they use one of the static "factory" methods of
TimeZone to obtain a suitable TimeZone
subclass.

You would instantiate this class directly only if you needed
to support a time zone with nonstandard daylight savings
time rules. In that case, you would use call
setStartRule() and setEndRule() to specify
the starting and ending dates of daylight savings time for
the time zone.